1. Field of the Invention
The present invention relates to a technology for application in an apparatus having a printer unit, in which a stable condition for printing operation can be realized by eliminating an inconvenience of lack of power when executing the printing operation using a battery.
2. Description of the Related Art
For an apparatus having a printer unit, and especially for a portable apparatus, a battery supplies power for each part or portion of the apparatus including the printer unit itself. For example, a printing operation is performed by the power supplied by the battery.
The printing operation performed by the printer unit generally requires a large amount of power, so that it requires a means of restraining the printing operation if the actual remaining power of the battery is lower than the amount of power required for enabling the thorough execution of the printing operation. As the means of restraining the printing operation, there is for example a way in which a voltage of the battery is monitored so that the printing operation is halted when the voltage becomes lower than a specified threshold value.
However, the method mentioned above of restraining the printing operation by monitoring the battery voltage has a problem that the printing operation is started if the voltage level is at the threshold value or higher, even when the battery does not have power enough to complete the printing operation. In such case, the printing operation is halted at the time the battery voltage becomes lower than the threshold voltage with the printing operation already started, thus causing a waste of printing paper.